Krill Oil, Fish Oil or BOTH ?

Fish Oil versus Krill Oil

Unlike fish oil supplements made from fatty fish like salmon and sardines, krill oil is made from tiny shrimp-like crustaceans. Both provide EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two omega-3 fatty acids found in fish. The concentration of omega-3 fatty acids, namely EPA and DHA are much lower in krill oil than fish oil.

The omega-3 fats in krill oil are more readily absorbed than those in fish oil. That’s because a large portion of the DHA and EPA in krill oil is bound to phospholipids. The physical properties of phospholipids allow them to dissolve in water, allowing them to be easily absorbed. In comparison, the omega-3s in fish oil, are attached to triglycerides, which don’t readily dissolve in water. The fact that krill oil contains readily absorbed phospholipids suggests that a smaller dose of omega-3’s from krill oil may be equally as effective as a higher concentration found in fish oil. Some manufacturers suggest that Krill Oil is 5X more potent than Fish Oil so 100mg of Krill Oil equates to 500mg of fish oil.  There’s some evidence to support this notion. A 2011 study published in demonstrated that three grams of krill oil (providing 543 mg EPA + DHA) and 1.8 grams of fish oil (864 mg EPA + DHA) raised blood levels of omega-3 fatty acids to the same degree.

Krill oil is also said to contain a higher concentration of astaxanthin, an antioxidant that comes from the algae krill feed on. (Astaxanthin gives krill and other crustaceans like shrimp and lobster their reddish-pink colour.)

So should you quit taking Fish oil ? Well, there’s very little research on the use of omega-3 fatty acids from krill oil. The vast majority of studies have used fish oil supplements. Furthermore,  I’m not saying krill oil isn’t worth taking as a means of boosting your omega-3 intake. It’s just too soon to know if it has the same numerous benefits attributed to omega-3’s from fish oil. Furthermore, at the present time krill oil is far more expensive than fish oil.

Bottom Line: Ideally, continue to take your fish oils and add some krill oil to the mix of Omega 3 essential fatty acids.


Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil.



Due to structural differences, bioavailability of krill oil, a phospholipid based oil, could be higher than fish oil, a triglyceride-based oil, conferring properties that render it more effective than fish oil in increasing omega-3 index and thereby, reducing cardiovascular disease (CVD) risk.


The objective was to assess the effects of krill oil compared with fish oil or a placebo control on plasma and red blood cell (RBC) fatty acid profile in healthy volunteers.


Twenty four healthy volunteers were recruited for a double blinded, randomized, placebo-controlled, crossover trial. The study consisted of three treatment phases including krill or fish oil each providing 600 mg of n-3 polyunsaturated fatty acids (PUFA) or placebo control, corn oil in capsule form. Each treatment lasted 4 wk and was separated by 8 wk washout phases.


Krill oil consumption increased plasma (p = 0.0043) and RBC (p = 0.0011) n-3 PUFA concentrations, including EPA and DHA, and reduced n-6:n-3 PUFA ratios (plasma: p = 0.0043, RBC: p = 0.0143) compared with fish oilconsumption. Sum of EPA and DHA concentrations in RBC, the omega-3 index, was increased following krill oilsupplementation compared with fish oil (p = 0.0143) and control (p < 0.0001). Serum triglycerides and HDL cholesterol concentrations did not change with any of the treatments. However, total and LDL cholesterol concentrations were increased following krill (TC: p = 0.0067, LDL: p = 0.0143) and fish oil supplementation (TC: p = 0.0028, LDL: p = 0.0143) compared with control.


Consumption of krill oil was well tolerated with no adverse events. Results indicate that krill oil could be more effective than fish oil in increasing n-3 PUFA, reducing n-6:n-3 PUFA ratio, and improving the omega-3 index.



Neuroprotective effect of astaxanthin (found in krill oil) against rat retinal ganglion cell death under various stresses that induce apoptosis and necrosis.



Astaxanthin is a type of carotenoid known to have strong antioxidant effects. The purpose of this study was to investigate whether astaxanthin confers a neuroprotective effect against glutamate stress, oxidative stress, and hypoxia-induced apoptotic or necrotic cell death in primary cultures of rat retinal ganglion cells (RGCs).


We found that under glutamate stress, RGC viability was reduced to 58%. Cultures with 1 nM, 10 nM, and 100 nM astaxanthin showed an increase in RGC viability of 63%, 74%, and 84%, respectively. Under oxidative stress, RGC viability was reduced to 40%, and astaxanthin administration resulted in increased viability of 43%, 50%, and 67%, respectively. Under hypoxia, RGC viability was reduced to 66%, and astaxanthin administration resulted in a significant increase in viability to 67%, 77%, and 93%, respectively. These results indicate that 100 nM astaxanthin leads to a statistically significant increase in RGC viability under the three kinds of stressors tested, compared to controls (Dunnett’s test, p<0.05). The apoptotic activity of RGCs under glutamate stress increased to 32%, but was reduced to 15% with 100 nM astaxanthin administration. Glutamate stress led to a 58% increase in DNA damage, which was reduced to 43% when cultured with 100 nM astaxanthin. Thus, 100 nM astaxanthin showed a statistically significant reduction in apoptosis and DNA damage in RGCs (Wilcoxon rank-sum test, p<0.05).


Our results suggest that astaxanthin has a neuroprotective effect against RGC death induced by glutamate stress, oxidative stress, and hypoxia, which induce apoptotic and necrotic cell death.



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